The invention relates to a motor-vehicle disk brake including:                a fork with at least two generally vertically oriented opposing arms, each having:                    an axial seat having a C-shaped section opening horizontally towards the opposite arm and delimited by an upper face and a lower face oriented generally horizontally;            a generally vertically oriented axial weight-bearing surface arranged beneath the seat;                        at least one brake pad including:                    two opposing lateral assembly lugs, each of which is received in a related seat of a related arm of the fork and is delimited by an upper surface oriented generally horizontally;            a lower vertically oriented surface related to each lug and located beneath the related lateral lug;                        for each lug of the brake pad, a pad spring that is attached to the related lug of the brake pad and that includes at least one lower sliding branch that cooperates with the lower face of said related seat and that loads said upper surface of the lug bearing vertically upwards against the upper face of said related seat;        for each arm of the fork, a laminar element made of spring steel that has at least:                    an upper axial sliding part having a C-shaped section that is received and locked in the related seat, that has a first lower flange, referred to as the sliding flange that is generally substantially horizontally oriented and that is interposed between the sliding branch of the pad spring and said lower face of the seat of the fork, and a second upper flange, referred to as the vertical support flange, that is oriented generally horizontally and that is interposed between said upper surface of the related lug of the brake pad and the upper face of said related seat;            at least one lower axial supporting part having a third flange, referred to as the transverse supporting flange, that prolongs the sliding flange, which extends in a plane orthogonal to the plane of the sliding flange, which is arranged in contact with said transverse weight-bearing surface of the arm, and that is able to form a transverse stop for said related lower surface of the brake pad.                        
A conventional disk brake includes a fork having at least two generally vertically oriented opposing arms that each have a lateral seat that extends axially and has a C-shaped section opening horizontally towards the opposite arm, and that includes a generally horizontally oriented upper face and a generally vertically oriented lower face.
The seat receives a laminar element made of spring steel that has at least one generally substantially horizontally oriented upper sliding flange that is interposed between the lug of the brake pad and the upper face of the seat, a generally vertically oriented vertical supporting flange that is interposed between the lug of the brake pad and the vertical face, and an elastic retaining flange that is arranged beneath the lug of the brake pad.
In such brakes, increasing the stiffness of the elastic retaining flange to improve retention of the brake pad creates transverse and vertical loads that, on account of the proximity of the elastic flange and of the vertical supporting flange, tend to deform the laminar element.
This prevents a flat-on-flat contact of the laminar element if the lug is not exerting significant pressure on the laminar element, in particular in relation to the vertical supporting flange thereof.
These loads are difficult to control on account of the design of the laminar element. Thus, for low pressures exerted by the lug of the brake pad, the brake pad is in an unpredictable position in relation to the lateral guide seats of the brake pad.
Moreover, during braking, the brake pad follows the rotation of the disk and is subject to a rotational torque exerted substantially on the theoretical center of contact between the brake pad and the disk, while being in transverse horizontal contact.
Theoretically, the resulting forces are aligned but, in consideration of manufacturing variations and uncertainty regarding the actual position of the transverse support between the lug and the laminar element caused by deformation of the element (as explained above), the resulting torque applied to the brake pad (about said theoretical center) may be positive or negative, causing the brake pad to rotate in the direction of rotation of the disk or, conversely, in the opposite direction, which results in unstable behavior of the brake pad.
To overcome this drawback, it is proposed to disconnect the vertical supporting face of the laminar element from the sliding face and from the horizontal supporting face according to a brake design described in the preamble.
Such disk brakes are known in the prior art.
Thus, in such a disk brake, the laminar element has a first lower sliding flange that is theoretically parallel to the second upper vertical supporting flange. Furthermore, the third transverse supporting flange, outside the seat, is orthogonal to the first lower sliding flange.
The first lower sliding flange has an anchoring or attachment tab or tongue that protrudes downwards and that cooperates with the lower face of the seat to anchor itself in this lower face of said seat.
The laminar element positions the lug of the brake pad such as to enable the pad spring to be load-bearing. Preferably, the lower flange provides the corresponding pre-stressing.